Stirring pulp in pulp-engines



(No Model.)

. G. P. HARLAN.

STIRRING PULP IN PULP ENGINES.

No. 308,255. Patented Nov. 18, 1884.

fi a NIT STATES GEORGE'F. HARLAN, OF ELKTON, MARYLAND.

STIRRING PULP IN PULP-ENGINES.

SPECIFICATION forming part of Letters Patent No. 308,255, dated November 18, 1884-.

' Application filed Angust 4, 1884. (N0 model.)

1'0 all whom it may concern Be it known that I, GEORGE F. HARLAN, a citizen of the United States, and a resident of Elkton, Cecil county, Maryland, have invented certain Improvements in Stirring Pulp in Pulp-Engines,of which the followingis a specification.

The object of my invention is to effect the thorough stirring or agitation of the mixture of water and pulp in the tub of a pulping-en gine, thereby insuring an effective circulation and the uniform pulping of the fiber.

This object I attain in the manner hereinafter set forth, reference being had to the accompanying drawings, in which- Figure .l. is a plan view of sufficient of a pulping-engine to illustrate my invention; Fig. 2, a transverse section of the same, and Fig. 3 a view illustrating another plan of carrying out my invention.

In Figs. 1 and 2, A is the oval tub of the rag-pulping engine; B, the central partitionplate; D, the pulping-roller; and F, the pulping-bed, all of these parts being constructed as usual.

In the operation of a pulping-engine the material to be pulped has a tendency to colleot-at those portions of the tub where it is free or comparatively free from the influence of the current, which flows in the direction of the arrows in Fig. 1, the portions thus collecting being insufficiently reduced by the action of the pulping roller and bed, and the pulp being consequently uneven in quality. This difficulty I overcome by projecting forcible streams or jets of air into the liquid contents of the tub, either continuously or at intervals, so that the settling of the pulp is prevented and the uniform action of the pulping mechanism thereupon insured.

In Figs. 1 and 2 I haveshown one means of distributing the air, said means consisting of a perforated pipe, a, located near the bottom of the tub and extending around the outer casing and around the pulping-bed. This pipea communicates through valved branches [2 with a pipe, (1, through which air under pressure is forced by any suitable means,the air escaping in the form of numerous forcible streams or jets into the mixture of water and pulp in the tub. Ifdesired,these air-j ets may be so directed as to facilitate the flow of the liquid in the course pointed out by the arrows; but this is not essential.

WVhen it is not convenient or desirable to place a permanent distributing-pipe in the tub, I propose to construct a stirrer or agitater, as shown in Fig. 3, for carrying out my invention. This stirrer consists of a tubular stem, f, having at the lower end branches h, and near the upper end handles 2', the upper end of the stem communicating through a flexible tube, m, with any convenient air compressor or reservoir.

The branched lower end of the pipe can be readily moved about over the bottom of the tub, so as to bring all portions of the-pulp under the influence of the jets issuing from the perforations.

I claim as my invention 1. The mode herein described of preventing the settling or lodging of pulp in the tub of a pulp-engine, said mode consisting in injecting forcible jets or streams of air into the liquid in said tub, as set forth.

2. The combination of the tub of a pulp-engine with a perforated pipe communicating with a supply of air under pressure, as set forth.

3. The within-described stirrer for pulp-err gines,said stirrer comprising the tubular stem f, perforated branches h, and flexible air-supply pipe m, as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

GEORGE F. HARLAN.

Witnesses:

J OHN M. CLAYTON, HARRY SMITH. 

